Abstract

Near infrared spectroscopy is a non-invasive technique for measuring relative blood volume and oxygen saturation in tissue. The authors have designed and built a research NIR-spectrometer which offers the flexibility to study changes in blood oxygen saturation (SO/sub 2/) and in blood volume (BV) during skeletal muscle pacing. The instrument consists of five 1 watt solid state lasers (780, 800, 830, 850 and 980 nm) fired sequentially at 5 /spl mu/s pulses for a 1 ms cycle, and a 5 mm/sup 2/ photodiode receiver. Features of the spectrometer include, rapid realtime data acquisition (1000 samples/s), receiver protection against ambient light, large dynamic optical power output adjustable for each wavelength, and portability. In vitro photon scattering experiments and linear response to blood oxygen saturation changes for differential absorption (780-850 nm) provide an accurate measure of changes in SO/sub 2/, while the 800 nm signal can be used as a measure of blood volume change independently of SO/sub 2/ (/spl plusmn/2%-SO/sub 2/ error). In addition, the 980 nm signal level is explored as an index of mean pathlength which may provide crucial information for determining absolute SO/sub 2/.

Talk to us

Join us for a 30 min session where you can share your feedback and ask us any queries you have

Schedule a call

Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.